TWI802347B - Tapered upper electrode for uniformity control in plasma processing - Google Patents

Abstract

An upper electrode for use in a substrate processing system includes a lower surface. The lower surface includes a first portion and a second portion and is plasma-facing. The first portion includes a first surface region that has a first thickness. The second portion includes a second surface region that has a varying thickness such that the second portion transitions from a second thickness to the first thickness.

Description

Tapered Top Electrode for Uniformity Control in Plasma Treatment

The present disclosure relates to systems and methods for controlling process uniformity in a substrate processing system.

The prior art description provided herein is for the purpose of generally presenting the context of the disclosure. The work of the presently listed inventors described in this prior art paragraph, and the descriptions of implementations that could not otherwise be identified as prior art at the time of filing, are not admitted, either expressly or implicitly, as prior art to this disclosure .

Substrate processing systems may be used to process substrates such as semiconductor wafers. Exemplary processes that may be performed on the substrate include, but are not limited to, chemical vapor deposition (CVD, chemical vapor deposition), atomic layer deposition (ALD, atomic layer deposition), conductor etching, dielectric etching, rapid thermal processing (RTP, rapid thermal processing), ion implantation, physical vapor deposition (PVD, physical vapor deposition), and/or other etching, deposition, or cleaning processes. The substrate may be placed on a substrate support (such as a susceptor, an electrostatic chuck (ESC, etc.)) located in a processing chamber of a substrate processing system. During processing, a gas mixture may be introduced into the processing chamber, and a plasma may be used to initiate and sustain chemical reactions.

The processing chamber contains various components including, but not limited to, substrate holders, gas distribution devices (such as showerheads, which may also correspond to upper electrodes), plasma confinement shutters, and the like. The substrate holder may include a ceramic layer positioned to support the wafer. For example, the wafer may be clamped to a ceramic layer during processing. The substrate support may comprise an edge ring disposed around an outer portion of the substrate support, for example, outside and/or adjacent to the periphery of the substrate support. The edge ring can be configured to confine the plasma to the volume above the substrate, optimize substrate edge handling performance, protect the substrate holder from erosion by the plasma, and the like. A plasma confinement shutter may be positioned around each of the substrate support and the showerhead to further confine the plasma within the volume above the substrate.

A top electrode for a substrate processing system includes a bottom surface. The lower surface includes a first portion and a second portion, and faces the plasma. The first portion includes a first surface area with a first thickness. The second portion includes a second surface region having a varying thickness such that the second portion transitions from the second thickness to the first thickness.

In other features, the second thickness corresponds to the height of the second portion at the center of the upper electrode. The first portion has a first radius, the second portion has a second radius, and the first radius is greater than the second radius. The second radius corresponds to a third radius of an electric field generated under the upper electrode during operation of the substrate processing system. The second radius is greater than or equal to the third radius.

In other features, the second surface region is sloped such that the second portion tapers from the second thickness to the first thickness. The slope of the second portion corresponds to an electric field generated under the upper electrode during operation of the substrate processing system. The second surface area is stepped. The second surface area is curved. The second surface area is convex. The second surface area is segmentally linear. The vertices and corners of the upper electrode are rounded according to a radius of 0.5 mm-10 mm. The lower surface further includes a plurality of holes configured to allow flow of process gas from a gas distribution device through the upper electrode.

In other features, a gas distribution device includes the upper electrode. The gas distribution device is equivalent to a shower head. A substrate processing system includes the gas distribution device.

A gas distribution device for a substrate processing system includes a rod portion and a bottom portion including an upper electrode. The upper electrode includes a lower surface. The lower surface includes a first portion and a second portion, and faces the plasma. The first portion has a first thickness and includes a first flat surface area. The second portion includes a second surface region having a varying thickness such that the second portion transitions from the second thickness to the first thickness.

In other features, the second surface region is sloped such that the second portion tapers from the second thickness to the first thickness. The second surface area is stepped. The second surface area is curved. The second surface area is convex. The second surface area is segmentally linear. The vertices and corners of the upper electrode are rounded according to a radius of 0.5 mm-10.0 mm.

A top electrode for a substrate processing system includes a first portion having a first surface area and a second portion extending beyond the first surface area and relative to the center of the top electrode Set symmetrically. The second portion has an apex and an outer periphery, and is tapered from the apex to the outer periphery.

In other features, the first surface region is flat and/or concave. The apex is aligned with the center of the upper electrode. The first portion has a first radius, the second portion has a second radius, and the first radius is greater than the second radius. The second radius corresponds to a third radius of an electric field generated under the upper electrode during operation of the substrate processing system. The second radius is greater than or equal to the third radius.

In other features, the slope of the second portion corresponds to an electric field generated under the top electrode during operation of the substrate processing system. The second portion is at least one of the following: stepped, curved, convex, and segmented straight. The first and second portions face the substrate. At least one of the first and second portions further includes a plurality of holes configured to allow flow of process gas from a gas distribution device through the upper electrode.

Other fields of applicability of the disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are presented for purposes of illustration only and are not intended to limit the scope of the disclosure.

Several aspects of the etching process may vary according to the characteristics of the substrate processing system, substrate, gas mixture, temperature, radio frequency (RF) and RF power, and the like. For example, flow patterns, and thus etch rates and etch uniformity, may vary according to the dimensions of components within a processing chamber of a substrate processing system. In several exemplary processes, the overall etch rate was varied with increasing distance between the upper surface of the substrate and the bottom surface of the gas distribution device. Also, the etch rate can vary from the center of the substrate to the outer periphery of the substrate. For example, in the outer periphery of the substrate, sheath bending and ion incident angle deflection may cause high aspect ratio contact window (HARC, high aspect ratio contact) profile deflection, and the reduction of plasma density may cause the decrease of etching rate and etching depth ( roll off), and chemical loading associated with reactive species (such as etchant and/or deposition precursors) may cause feature critical dimension (CD, critical dimension) non-uniformity. Also, substances such as etch by-products may be redeposited on the substrate. The etch rate may vary according to other process parameters including, but not limited to, RF and RF power, temperature, and gas flow rate across the upper surface of the substrate.

Components that may affect the processing of the substrate include, but are not limited to, gas distribution devices (such as showerheads, which may also correspond to upper electrodes), plasma confinement shields, and/or include bottom plates, one or more edge rings, coupling Substrate holders for rings, etc. For example, a dielectric plasma etch process may use a top electrode with a flat bottom surface facing the plasma. In some applications, high radio frequency (RF) power supplies (eg, RF power supplies set at 60 MHz, 40 MHz, etc.) may cause a center-peaked plasma distribution in the processing volume above the substrate. Also, high bias powers (e.g. bias powers set at 400 kHz, 2 MHz, etc.) may cause plasma density spikes in the edge regions of the substrate (e.g. edge spikes between 80-150 mm from the center) . A plasma distribution comprising a central peak and edge peaks may be referred to as a "W"-shaped radial plasma inhomogeneity.

Therefore, non-uniform plasma distribution may cause non-uniform processing results (eg, etch). In some applications, such as high aspect ratio etch applications, radial plasma non-uniformities may cause profile skew in addition to etch non-uniformities across the substrate. As the aspect ratio increases (eg, aspect ratios greater than 50), the tolerance for profile deflection decreases and very small deflection (eg, less than 0.1°) would be desired.

Systems and methods in accordance with principles of the present disclosure modify the size and geometry (eg, profile) of the upper electrode to control radial plasma distribution and uniformity. For example, using a top electrode with a tapered (ie, angled, sloped, skewed, curved, shaped, etc.), plasma-facing lower surface. In one example, the upper electrode tapers radially from the center towards the outer periphery of the upper electrode. In some examples, the taper may not extend to the outer perimeter of the upper electrode, but may stop a distance radially inward of the outer perimeter. In other examples, the taper may extend to the outer perimeter of the upper electrode. Thus, the thickness of the upper electrode varies based on the radial distance from the center of the upper electrode.

The size of the taper (eg, corresponding thickness at a radial distance from the upper electrode, radius or length of the taper, etc.) may be selected according to the desired radial plasma distribution. For example, the thickness of the taper can be determined according to the peak plasma density at the center of the top electrode. Instead, the radius or length of the taper can be determined according to the length scale of the radial plasma density gradient. The thickness of the taper at the center of the upper electrode is selected to reduce and eliminate the peak plasma density at the center of the process volume, and the radius or length of the taper is selected to reduce (i.e., eliminate) and minimize the plasma density in the radial direction. Plasma inhomogeneity. Therefore, profile skew and etch non-uniformity caused by plasma non-uniformity in high aspect ratio etching can be minimized.

Referring now to FIG. 1 , an exemplary substrate processing system 100 is shown. By way of example only, the substrate processing system 100 may be used to perform etching, deposition, and/or other suitable substrate processing using RF plasma. The substrate processing system 100 includes a processing chamber 102 that encloses the other components of the substrate processing system 100 and houses an RF plasma. The substrate processing chamber 102 includes a top electrode 104 and a substrate support 106 such as an electrostatic chuck (ESC). During operation, a substrate 108 is positioned on the substrate holder 106 . Although a particular substrate processing system 100 and chamber 102 are shown as an example, the principles of the present disclosure may be applied to other types of substrate processing systems and chambers.

For example only, the upper electrode 104 may include a gas distribution device, such as a showerhead 109 that introduces and distributes the process gas. Showerhead 109 may comprise a stem portion comprising one end connected to the top surface of the processing chamber. The bottom portion is generally cylindrical and extends radially outwardly from opposite ends of the stem portion at a location spaced from the top surface of the processing chamber. The substrate-facing surface or faceplate of the bottom portion of the showerhead includes a plurality of holes through which process or purge gas flows. Alternatively, the upper electrode 104 may comprise a guide plate, and the process gas may be introduced in another manner. The upper electrode 104 in accordance with principles of the present disclosure may have a tapered, plasma-facing lower surface as detailed below.

The substrate holder 106 includes a conductive bottom plate 110 as a lower electrode. The bottom plate 110 supports a ceramic layer 112 . In several examples, ceramic layer 112 may comprise a heating layer, such as a ceramic multi-zone heating plate. A heat-resistant layer 114 , such as a bonding layer, may be disposed between the ceramic layer 112 and the base plate 110 . The bottom plate 110 may include one or more refrigerant passages 116 for allowing the refrigerant to flow through the bottom plate 110 . The substrate support 106 may include an edge ring 118 positioned to surround the outer perimeter of the substrate 108 .

The RF generation system 120 generates RF power and outputs it to one of the upper electrode 104 and the lower electrode (eg, the bottom plate 110 of the substrate holder 106 ). The other of the upper electrode 104 and the bottom plate 110 may be DC grounded, RF grounded or floated. For example only, the RF generation system 120 may include an RF power generator 122 that generates RF power that is fed to the top electrode 104 or the bottom plate 110 through a matching and distribution network 124 . In other examples, plasma can be generated inductively or remotely. Although, as shown for exemplary purposes, the RF generation system 120 is equivalent to a capacitively coupled plasma (CCP) system, the principles of the present disclosure may also be implemented in other suitable systems, e.g., for exemplary purposes only , Transformer coupled plasma (TCP, transformer coupled plasma) system, CCP cathode system, remote microwave plasma generation and delivery system, etc.

The gas delivery system 130 includes one or more gas sources 132-1, 132-2, . . . and 132-N (collectively referred to as gas sources 132), where N is an integer greater than zero. A gas source supplies one or more gas mixtures. The gas source can also supply purge gas. Vaporized precursors can also be used. Gas source 132 is connected by valves 134-1, 134-2, ... and 134-N (collectively valves 134) and mass flow controllers 136-1, 136-2, ... device 136) to the manifold 140. The output of manifold 140 is fed to processing chamber 102 . For example only, the output of manifold 140 is fed to showerhead 109 .

The temperature controller 142 may be connected to a plurality of heating elements, such as thermal control elements (TCE) 144 disposed in the ceramic layer 112 . For example, heating elements 144 may include, but are not limited to, large heating elements corresponding to individual zones in a multi-zone heating plate and/or an array of micro heating elements arranged across multiple zones of a multi-zone heating plate. The temperature controller 142 can be used to control a plurality of heating elements 144 to control the temperature distribution of the substrate holder 106 and the substrate 108 .

The temperature controller 142 can communicate with the refrigerant assembly 146 to control the flow of refrigerant through the channel 116 . For example, the refrigerant assembly 146 may include a refrigerant pump and a storage tank. The temperature controller 142 operates the coolant assembly 146 to selectively flow coolant through the channels 116 to cool the substrate holder 106 .

Valve 150 and pump 152 may be used to evacuate etch by-products from processing chamber 102 . The system controller 160 may be used to control the components of the substrate processing system 100 . One or more robots 170 may be used to transfer substrates onto and remove substrates from the substrate holder 106 . For example, the robot 170 may transfer substrates between the EFEM 171 and the mount chamber 172, between the mount chamber and the VTM 173, between the VTM 173 and the substrate holder 106, and so on. Although shown as a separate controller, temperature controller 142 may be implemented within system controller 160 . In several examples, a protective seal 176 may be disposed around the perimeter of the bonding layer 114 between the ceramic layer 112 and the base plate 110 .

In several examples, the processing chamber 102 may include a plasma confinement shield 180, such as a C-shaped shield. A C-shaped shield 180 is disposed around the top electrode 104 and the substrate holder 106 to confine the plasma within the plasma region 182 . In some examples, the C-shape shield 180 includes a semiconductor material, such as silicon (Si) or polysilicon. C-shaped shield 180 may include one or more slots 184 positioned to allow gas to flow out of plasma region 182 to be exhausted from processing chamber 102 via valve 150 and pump 152 .

Referring now to FIG. 2 , an exemplary substrate processing chamber 200 including a substrate support 204 and a gas distribution device 208 (eg, a showerhead) is shown. The substrate holder 204 includes a bottom plate 212 that may serve as a bottom electrode. Conversely, the gas distribution device 208 may include an upper electrode 216 . In some examples, the upper electrode 216 may include an inner electrode 220 and an outer electrode 224 . For example, the inner electrode 220 and the outer electrode 224 may respectively correspond to a disk and an annular ring (ie, the outer electrode 224 surrounds the outer edge of the inner electrode 220 ). For simplicity, as used herein, the disclosure will collectively refer to the inner electrode 220 and the outer electrode 224 as the upper electrode 216 .

Base plate 212 supports ceramic layer 228 . Ceramic layer 228 supports substrate 232 . In several examples, bonding layer 236 is disposed between ceramic layer 228 and base plate 212 , and protective seal 240 is disposed around a perimeter of bonding layer 236 between ceramic layer 228 and base plate 212 . The substrate support 204 may include an edge ring 242 positioned to surround the outer perimeter of the substrate 232 . In several examples, the processing chamber 200 may include a plasma confinement shield 244 disposed about the upper electrode 216 . Top electrode 216 , substrate support 204 (eg, ceramic layer 228 ), edge ring 242 , and plasma confinement shield 244 define a processing volume (eg, plasma region) 248 above substrate 232 .

As shown in FIG. 2, the lower surface 252 of the upper electrode 216 is substantially flat and faces the plasma. For example, lower surface 252 is flat, has a horizontal orientation relative to processing chamber 200 , and is parallel to substrate 232 and ceramic layer 228 . As shown at 256, the upper electrode 216 with a flat lower surface 252 results in a centrally peaked plasma density distribution ("plasma distribution"). Thus, the plasma distribution is non-uniform and includes a central peak 260 (i.e., a density peak in the vertical z-direction that is centrally located relative to the process volume 248 and upper electrode 216), and can be distributed in the r-direction (i.e., the radial direction). decrease. The plasma distribution may further include an outer peak 264 . The plasma distribution shown in FIG. 2 can cause process non-uniformities such as profile skew and etch non-uniformity of the substrate 232 (eg, in the mid-radius region of the substrate 232).

For example, the plasma distribution is caused by the corresponding RF electric field (E-field) distribution and its power deposition into the plasma. The E-field distribution is dependent on the effective RF wavelength in the generated plasma corresponding to the applied RF, so the E-field distribution is generally related to the plasma distribution. For example, in FIG. 2 , the E-field distribution may be similar to the plasma distribution shown at 256 . Thus, the E-field distribution may be larger in the region corresponding to the central peak 260 of the plasma distribution, and decrease in the r-direction (ie, decrease with increasing radius). In other words, the E-field distribution exhibits radial attenuation over a certain distance.

In a CCP system, the RF power used to generate the plasma produces a capacitive component Ez of the E-field distribution in the vertical direction, which causes capacitive plasma heating. Thus, capacitive plasma heating is increased in the region of the central peak 260 of the plasma distribution when the effective RF wavelength is close to or smaller than the substrate radius. Conversely, in the region of the central peak 260, the inductance component Er of the E-field distribution in the radial direction is substantially zero. In other words, the E field distribution corresponding to the plasma distribution shown in FIG. 2 may correspond to E=Ez, where Er=0 in the region of the central peak 260 .

Referring now to FIG. 3, another exemplary substrate processing chamber 300 is shown that includes a substrate support 304 and a gas distribution device 308, such as a showerhead. The substrate holder 304 includes a bottom plate 312 that may serve as a bottom electrode. Conversely, the gas distribution device 308 may include an upper electrode 316 . In some examples, the upper electrode 316 may include an inner electrode 320 and an outer electrode 324 . For example, the inner electrode 320 and the outer electrode 324 may correspond to concentric disks and rings, respectively (ie, the outer electrode 324 surrounds the outer edge of the inner electrode 320 ). For simplicity, as used herein, the disclosure will collectively refer to the inner electrode 320 and the outer electrode 324 as the upper electrode 316 .

Base plate 312 supports ceramic layer 328 . Ceramic layer 328 supports substrate 332 . In several examples, bonding layer 336 is disposed between ceramic layer 328 and base plate 312 , and protective seal 340 is disposed around a perimeter of bonding layer 336 between ceramic layer 328 and base plate 312 . The substrate support 304 may include an edge ring 342 positioned to surround the outer perimeter of the substrate 332 . In several examples, the processing chamber 300 may include a plasma confinement shield 344 disposed about the upper electrode 316 . Top electrode 316 , substrate support 304 (eg, ceramic layer 328 ), edge ring 342 , and plasma confinement shield 344 define a processing volume (eg, plasma region) 348 above substrate 332 .

As shown in FIG. 3, the lower surface 352 of the upper electrode 316 is tapered and faces the plasma. For example, lower surface 352 includes a generally planar first portion 356 having a first thickness, and a tapered (ie, sloped) second portion 360 . The second portion 360 decreases from a height H at the center 364 of the lower surface 352 as the radius R (ie, the distance from the center 364 ) increases. Accordingly, the thickness of the second portion 360 changes (eg, decreases) as the radius increases. As shown at 368, the upper electrode 316 with the tapered lower surface 352 suppresses the central peak of the plasma distribution. In other words, the plasma distribution shown in FIG. 3 does not include the central peak 260 shown in FIG. 2 . Also, the tapered second portion 360 promotes plasma diffusion from the small gap region (i.e., in the central region 372) to the large gap region (i.e., in the outer region 376), and thus reduces the plasma density in the central region 372. density.

Compared to the example of FIG. 2 , the tapered lower surface 352 causes a reduced capacitive E-field component Ez in the vertical direction and a non-zero inductive E-field component Er in the radial direction in the central region 372 . The inductive component Er provides inductive plasma heating, which effectively generates the plasma. Also, the inductance component Er increases as the radius R increases. Therefore, since the inductance component Er increases with the radius and the capacitance component Ez decreases with the radius, the inductance component Er compensates for changes in plasma distribution and heating caused by the decrease of the capacitance component Ez. In other words, the E field E corresponding to the plasma distribution shown in FIG. 3 may be equivalent to E = Ez + Er, which combines both the capacitive component Ez and the inductive component Er and thus results in a more uniform electric field with a suppressed central peak. Pulp distribution.

Referring now to FIG. 4, another exemplary substrate processing chamber 400 including a substrate support 404 and a gas distribution device 408, such as a showerhead, is shown. The substrate holder 404 includes a bottom plate 412 that may serve as a bottom electrode. Conversely, the gas distribution device 408 may include an upper electrode 416 . In some examples, the upper electrode 416 may include an inner electrode 420 and an outer electrode 424 . For example, the inner electrode 420 and the outer electrode 424 may correspond to concentric disks and rings, respectively (ie, the outer electrode 424 surrounds the outer edge of the inner electrode 420 ). For simplicity, as used herein, the disclosure will collectively refer to the inner electrode 420 and the outer electrode 424 as the upper electrode 416 .

Base plate 412 supports ceramic layer 428 . Ceramic layer 428 supports substrate 432 . In several examples, bonding layer 436 is disposed between ceramic layer 428 and base plate 412 , and protective seal 440 is disposed around a perimeter of bonding layer 436 between ceramic layer 428 and base plate 412 . The substrate support 404 may include an edge ring 442 positioned to surround the outer perimeter of the substrate 432 . In several examples, the processing chamber 400 may include a plasma confinement shield 444 disposed about the upper electrode 416 . Top electrode 416 , substrate support 404 (eg, ceramic layer 428 ), edge ring 442 , and plasma confinement shield 444 define a processing volume (eg, plasma region) 448 above substrate 432 .

As shown in FIG. 4, the lower surface 452 of the upper electrode 416 is tapered and faces the plasma. For example, lower surface 452 includes a generally planar first portion 456 having a first thickness, and a tapered (ie, sloped) second portion 460 . The second portion 460 decreases from a height H at the center 464 of the lower surface 452 as the radius R (ie, the distance from the center 464 ) increases. Accordingly, the thickness of the second portion 460 changes (eg, decreases) as the radius increases. As shown at 468, the upper electrode 416 with the tapered lower surface 452 suppresses the central peak of the plasma distribution. In other words, the plasma distribution shown in FIG. 4 does not include the central peak 260 shown in FIG. 2 . Also, the tapered second portion 460 promotes plasma diffusion from the small gap region (i.e., in the central region 472) to the large gap region (i.e., in the outer region 476), and thus reduces the plasma density in the central region 472. density.

Similar to the example of FIG. 3 , in the central region 472 , the tapered lower surface 452 causes a reduced capacitive E-field component Ez in the vertical direction and produces a non-zero inductive E-field component Er in the radial direction. Therefore, since the inductance component Er increases with the radius and the capacitance component Ez decreases with the radius, the inductance component Er compensates for changes in plasma distribution and heating caused by the decrease of the capacitance component Ez. Compared to the example of FIG. 3 , the taper of second portion 460 has a smaller slope and is more gradual than the taper of second portion 360 (ie, the thickness of second portion 460 decreases as the radius increases. system decreases at a lower rate or angle). Accordingly, plasma density uniformity and profile skew across the substrate 432 are improved.

As shown in FIGS. 3 and 4, the dimensions of the second portions 360 and 460 (such as height H, radius R, angle of slope, etc.) can be selected according to the characteristics of the E field and plasma distribution in each processing chamber 300 and 400. ). For example, the height H of the second portions 360 and 460 may be selected according to the maximum values of the E-field and plasma density in the central regions 372 and 472 . Instead, the radius R of the second portions 360 and 460 may be selected according to the radius of the corresponding E-field and plasma density gradient. In one example, the radius R may be greater than or equal to the length scale of the E-field and plasma radial gradient. For example, the radius R of the second portion 360 or 460 may be at least 75 mm if the radial attenuation of the E field and plasma density reaches a trough at 75 mm. In other examples, the respective slopes of the second portions 360 and 460 may correspond to the slopes of the E-field and the plasma density. In other words, as the E-field and plasma density decay radially, the height H of the second portion 360 or 460 may decrease radially in proportion to the decay of the E-field and plasma density.

In this manner, the size of the upper electrode 316/416 may be selected according to the operating characteristics of a particular processing chamber. For example, properties such as plasma distribution, E-field, etc. can be initially observed and measured (eg with a conventional upper electrode installed). The dimensions of the top electrode in accordance with the principles of the present disclosure can then be determined based on the measured chamber operating characteristics. In some examples, the vertices and corners of the upper electrodes 316/416 (for example, at the oblique transition of the vertices 380/480) may be rounded with a radius of 0.5 mm-10.0 mm.

As shown in Figures 5A, 5B, and 5C, upper electrode 500 may include other exemplary lower surfaces 504-1, 504-2, and 504-3 (collectively lower surface 504) configured to modify plasma distribution. For example, as shown in FIG. 5A , the lower surface 504 - 1 of the upper electrode 500 may be stepped or stepped. In other words, the lower surface 504-1 may have a thickness that decreases in a stepwise manner from the central region 508 of the upper electrode 500 to the outer region 512 of the upper electrode. As shown in FIG. 5B , the lower surface 504 - 2 of the upper electrode 500 may be curved (eg convex). In other words, the lower surface 504-2 may have a thickness that decreases in a curvilinear manner from the central region 508 of the upper electrode 500 to the outer region 512 of the upper electrode. As shown in FIG. 5C , the lower surface 504 - 3 may be sloped or sloped in a segmented straight line. In other words, the lower surface 504-3 may have a thickness that decreases and/or increases at different angles from the central region 508 of the upper electrode 500 to the outer region 512 of the upper electrode. For example, the thickness of the lower surface 504-3 may decrease at a first angle in the central region 508, decrease at a second angle in the inner region 516, increase at a third angle in the outer region 520, and increase at a third angle in the outer region 512. The fourth angle decreases. Therefore, the lower surface 504 can be selected and configured according to the plasma distribution characteristics in a particular substrate processing chamber. In some examples, the vertices and corners of the upper electrode 500 and the lower surface 504 may be rounded with a radius of 0.5 mm-10.0 mm.

As shown in Figures 6A and 6B, upper electrode 600 may include other exemplary lower surfaces 604-1 and 604-2 (collectively lower surface 604) configured to modify plasma distribution. For example, as shown in FIG. 6A , the lower surface 604 - 1 of the upper electrode 600 may be curved (eg convex) in the central region 608 and concave in the outer region 612 . In other words, the lower surface 604-1 transitions from the convex central region 608 to the concave outer region 612, and both the central region 608 and the concave region 612 vary in thickness. For example, lower surface 604 - 1 may have a thickness that decreases curvilinearly from central region 608 into outer region 612 and then increases from outer region 612 to edge region 616 . In the edge region 616 shown in FIG. 6A, the lower surface 604-1 may be flat.

As shown in FIG. 6B , the lower surface 604 - 2 of the upper electrode 600 may be tapered (eg, sloped) in the central region 608 and concave in the outer region 612 . In other words, the lower surface 604-2 transitions from the tapered central region 608 to the concave outer region 612, and both the central region 608 and the concave region 612 vary in thickness. For example, lower surface 604 - 2 may have a thickness that decreases linearly from central region 608 into outer region 612 and then increases from outer region 612 to edge region 616 . In the edge region 616 shown in FIG. 6B , the lower surface 604 - 2 may be convex, radiused, rounded, or the like.

The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes certain examples, the true scope of this disclosure should not be so limited since other variations will become apparent upon study of the drawings, specification, and following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Furthermore, while each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in any other embodiment, and/or in combination with features thereof (even if the combination is not explicitly described). In other words, the described embodiments are not mutually exclusive, and substitutions of one or more embodiments for each other remain within the scope of this disclosure.

Spatial and functional relationships between elements (e.g., in modules, circuit elements, semiconductor layers, etc.) Various terminology descriptions of "on", "above", "under", and "set". Unless expressly described as "directly," when a relationship between a first and second element is described in the above disclosure, the relationship can be that there are no other intervening elements between the first and second elements. a direct relationship between the first and second elements, but also an indirect relationship in which one or more intervening elements (either spatially or functionally) exist between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be construed to mean the logic (A OR B OR C) using a non-exclusive logical OR, and should not be construed to mean "at least one of A , at least one of B, and at least one of C."

In several embodiments, the controller is part of a system that may be part of the examples described above. Such systems may include semiconductor processing equipment including processing tools, chambers, platforms for processing, and/or specific processing components (wafer susceptors, gas flow systems, etc.). These systems may be integrated with electronics used to control the operation of these systems before, during, and after processing semiconductor wafers or substrates. The electronic components may be referred to as "controllers" which may control the various components or sub-components of the system. The controller can be programmed to control any of the processes disclosed herein, including delivery of process gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum, depending on process requirements and/or system type. Settings, Power Settings, Radio Frequency (RF) Generator Settings, RF Matching Circuit Settings, Frequency Settings, Flow Rate Settings, Fluid Delivery Settings, Position and Operation Settings, Access to and Exit from a Tool Connected or Interfaced with a Specific System, and Others Wafer handling for handling tools and/or load chambers.

Generally speaking, the controller can be defined as an electronic component with various integrated circuits, logic, memory, and/or software, which receives instructions, issues instructions, controls operations, performs cleaning operations, and performs end-point measurements. The integrated circuit may include a chip in the form of firmware and stored with program instructions, a digital signal processor (DSP, digital signal processor), a chip defined as an application specific integrated circuit (ASIC, application specific integrated circuits), and and/or one or more microprocessors, or microcontrollers that execute programmed instructions (eg, software). Program instructions may be instructions sent to the controller in the form of various individual settings (or program files) to define operating parameters for implementing specific processes on a semiconductor wafer or for a system. In some embodiments, these operating parameters may be part of a recipe defined by a process engineer to create a pattern on one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or One or more processing steps are implemented during the processing of the die or die.

In some embodiments, the controller can be part of or coupled to a computer that is integrated with the system, or coupled to the system, or networked to the system, or a combination thereof. For example, the controller may reside in the "cloud" or be all or part of the fab's main computer system, which allows remote access for wafer processing. The computer can remotely access the system to monitor the current progress of machining operations, check the history of past machining operations, check trends or performance indicators from multiple machining operations, change the parameters of the current process, and set the process according to the current process step, or start a new process. In some examples, a remote computer (eg, a server) can provide the processing recipe to the system over a network, which can include a local area network or the Internet. The remote computer may include a user interface that enables input or programming of parameters and/or settings that are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in the form of data specifying parameters for each processing step to be performed during one or more operations. One should understand that these parameters can be specific to the type of processing to be performed and the type of tool the controller interfaces or controls. Thus, as noted above, the controllers may be allocated, for example, by including one or more separate controllers that are networked together and function for a common purpose, such as processing and control as described herein. device. An example of a controller assigned for this purpose could be one or more integrated circuits on the chamber that are connected to a remote device (e.g. platform level or as part of a remote computer) or multiple integrated circuits in communication to jointly control processes on the chamber.

Exemplary systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin cleaning chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel etch Chamber or module, physical vapor deposition (PVD) chamber or module, chemical vapor deposition (CVD) chamber or module, atomic layer deposition (ALD) chamber or module, atomic layer etching (ALE, atomic layer etch chambers or modules, ion implantation chambers or modules, coating development (track) chambers or modules, and any other semiconductor wafers that may be incorporated or used in the processing and/or fabrication of semiconductor wafers processing system.

As noted above, depending on the processing steps to be performed by the tool, the controller may communicate with one or more of: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, Adjacent tools, adjacent tools, tools located throughout the fab, host computer, another controller, or tool locations and/or load lanes used for material handling to transport wafer containers to and from semiconductor fabs tool.

100: Substrate processing system 102: processing chamber 104: Upper electrode 106: Substrate support 108: Substrate 109: sprinkler head 110: Bottom plate 112: ceramic layer 114: heat-resistant layer 116: Refrigerant channel 118: edge ring 120:RF generation system 122: RF power generator 124:Matching and distribution network 130: Gas delivery system 132-1: Gas source 132-2: Gas source 132-N: Gas source 134-1: Valve 134-N: valve 136-1: Mass flow controller 136-N: Mass flow controller 140: Manifold 142: Temperature controller 144: heating element 146: Refrigerant components 150: valve 152: pump 160: system controller 170: Robot 171:EFEM 172: Bearing room 173: VTM 176: Protective seal 180: Plasma Confinement Shutter 182: Plasma area 184: slot 186:Aerosol delivery system 200: substrate processing chamber 204: Substrate support 208: Gas distribution device 212: bottom plate 216: Upper electrode 220: inner electrode 224: External electrode 228: ceramic layer 232: Substrate 236: Bonding layer 240: Protective seal 242: edge ring 244: Plasma Confinement Shutter 248: Processing volume 252: lower surface 260: Center Spike 264: Outer Spike 300: substrate processing chamber 304: Substrate support 308: gas distribution device 312: Bottom plate 316: Upper electrode 320: inner electrode 324: External electrode 328: ceramic layer 332: Substrate 336: joint layer 340: Protective seal 342: edge ring 344: Plasma Confinement Shutter 348: Processing volume 352: lower surface 356:Part One 360: Part Two 364: center 372: Central area 376: Outer area 380: Vertex 400: substrate processing chamber 404: substrate support 408: Gas distribution device 412: bottom plate 416: Upper electrode 420: inner electrode 424: External electrode 428: ceramic layer 432: Substrate 436: joint layer 440: Protective seal 442: edge ring 444: Plasma Confinement Shutter 448: Processing volume 452: lower surface 456: Part 1 460: Part Two 464: center 472: Central area 476: Outer area 480: Vertex 500: Upper electrode 504-1: lower surface 504-2: lower surface 504-3: lower surface 508: central area 512: Outer area 516: Inner area 520: Chinese and foreign areas 600: Upper electrode 604-1: lower surface 604-2: lower surface 608: Central area 612: Outer area 616: Edge area

The disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

FIG. 1 is an exemplary substrate processing system in accordance with the principles of the present disclosure;

FIG. 2 is an exemplary substrate processing chamber;

3 is a substrate processing chamber including an exemplary top electrode in accordance with principles of the present disclosure;

4 is a substrate processing chamber including another exemplary top electrode in accordance with principles of the present disclosure; and

5A, 5B, and 5C are exemplary top electrodes in accordance with principles of the present disclosure.

6A and 6B are exemplary top electrodes in accordance with principles of the present disclosure.

In the drawings, reference symbols may be reused to indicate similar and/or identical elements.

600: Upper electrode

604-1: lower surface

608: Central area

612: Outer area

616: Edge area

Claims (18)

An upper electrode for a substrate processing system, the upper electrode comprising: a lower surface, wherein the lower surface comprises a central region, the thickness of which decreases from the center of the upper electrode to a first radius, and a concave outer region, the thickness varies from the first radius to a second radius, the second radius being greater than the first radius, wherein the radial distance from the first radius to the second radius is greater than the first radius, an edge region , extending from the second radius to a third radius, the third radius being larger than the second radius, and a plurality of holes arranged to allow process gas to flow through the upper electrode, wherein the first radius, the second radius and The third radius is selected to minimize radial non-uniformity in plasma distribution generated between the upper electrode and substrate support during substrate processing, wherein the thickness of the upper electrode is selected to suppress the center of the plasma distribution The peak, and wherein the thickness of the edge region is selected to reduce edge peaking of the plasma distribution. The upper electrode for a substrate processing system as claimed in claim 1, wherein the thickness of the upper electrode is largest at the center of the upper electrode. The upper electrode for a substrate processing system as claimed in claim 1, wherein the entire lower surface located inside the edge region is curved. The upper electrode for a substrate processing system as claimed in claim 1, wherein the lower surface transforms from concave in the outer region to flat in the edge region as the radial distance from the central region increases. The upper electrode for a substrate processing system as claimed in claim 1, wherein the central region tapers from the center of the upper electrode to the first radius. The upper electrode for a substrate processing system as claimed in claim 1, wherein the first radius corresponds to a radius of an electric field generated under the upper electrode during operation of the substrate processing system. The upper electrode for a substrate processing system according to claim 6, wherein the first radius is greater than or equal to the radius of the electric field. A substrate processing chamber, which includes a shower head and the upper electrode of Claim 1. The substrate processing chamber according to claim 8, further comprising the substrate holder, wherein the upper electrode is located above the substrate holder and faces the substrate holder. A showerhead for a substrate processing chamber comprising: an upper electrode having a lower surface; a plurality of holes in the lower surface, the plurality of holes being configured to allow process gas to flow from the showerhead through the upper electrode and enter the substrate processing chamber; A central region, the thickness of which decreases from the center of the upper electrode to the first radius; an outer region, wherein the outer region is located radially outward of the central region, the outer region is concave, the outer region the thickness varies from the first radius to a second radius, the second radius is greater than the first radius, and the radial distance from the first radius to the second radius is greater than the first radius; and an edge a region extending from the second radius to a third radius such that the outer region is located between the central region and the edge region, wherein the first radius, the second radius and the third radius are selected to treat the substrate during processing The radial inhomogeneity of the plasma distribution produced between the upper electrode and the substrate support is minimized, wherein the thickness of the upper electrode is selected to suppress the central peak of the plasma distribution, and wherein the thickness of the edge region is Select to reduce the edge peaking of the plasma distribution. The showerhead for a substrate processing chamber as claimed in claim 10, wherein the thickness of the upper electrode is greatest at the center of the upper electrode. The showerhead for a substrate processing chamber as claimed in claim 11, wherein the thickness of the edge region is greater than the thickness of the outer region. The showerhead for a substrate processing chamber as claimed in claim 10, wherein the entire lower surface located inside the edge region is curved. The showerhead for a substrate processing chamber as claimed in claim 10, wherein the lower surface transitions from concave in the outer region to flat in the edge region as the radial distance from the central region increases. The showerhead for a substrate processing chamber as claimed in claim 10, wherein the central region tapers from the center of the upper electrode to the first radius. The showerhead for a substrate processing chamber of claim 10, wherein the first radius corresponds to a radius of an electric field generated under the upper electrode during operation of the substrate processing chamber. The showerhead for a substrate processing chamber as claimed in claim 16, wherein the first radius is greater than or equal to the radius of the electric field. A substrate processing chamber, which includes the shower head of claim 10.

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